1. Technical Field
The present disclosure generally relates to electrodes and, more particularly, to wire-free and stud-free electrode assemblies capable of use in connection with a garment.
2. Discussion of Related Art
Skin-applied electrode assemblies are well known for use in medical applications such as cardiac pacing, electrocardiograph (ECG) monitoring, and defibrillation. Typically, these electrode assemblies are attached to a wire lead or cable that is attached at its opposite end to a connector of a medical device or medical device instrumentation. Electrode assemblies generally include an electrode, e.g., a conductor such as a thin layer of metal, resting on a foam backing. The electrode is typically covered with a conductive gel that contacts a patient's skin. In addition, for one or more reasons, e.g., to prevent the adhesive gel from drying out, to maintain the electrodes in a sanitary condition, and to cover the adhesive until a caregiver is ready to adhere the electrode to the patient, a release sheet, e.g., a plastic cover, is positioned over the adhesive and/or conductive gel of each electrode.
Concerning the operation and functionality of electrodes, electrodes are used to transmit electrical signals between the body of patient and external medical equipment, such as a monitoring, diagnostic, or stimulating device. It has been known that electrical signals, which are obtained via electrodes applied to the body, can be evaluated in connection with various diagnostic procedures. The application of electrodes on the body surface should provide reliability and stability of position. Thus, large contact areas are used for obtaining signals in a reliable manner in order to ensure acceptable electric contact between the electrode and the skin of a patient. Two basic principles have become widespread for attaching electrodes to the skin of a patient. Electrodes are either attached to the body surface as individually adhering electrodes or the electrodes are attached to a carrier means, which ensures the reliable seating of the electrodes in one or more desired positions.
Concerning the different types of electrodes, conventional electrodes may include passive electrodes and active electrodes. Passive electrodes include a metal disc with a connecting wire to electronic circuitry. This simplicity makes this type of electrode low cost. However, these electrodes are prone to noise and can require numerous noise canceling techniques to achieve satisfactory performance. One noise canceling technique, to minimize impedance at the skin-electrode interface and to minimize interference, involves conditioning the skin where the electrode is to be applied. On the other hand, active electrodes may include resistive and capacitive active electrodes. Resistive active electrodes use a direct current path between the subject's skin and the input of an operational amplifier to acquire a signal. Capacitive active electrodes do not make electrical contact with the subject's skin, but have a capacitive link between subject's skin and the electrode.
Biomedical electrodes, as described in the present disclosure, are resistive active electrodes. Biomedical electrodes are commonly used in therapeutic and diagnostic medical applications including, e.g., a variety of signal based rehabilitative procedures, ECG or transcutaneous electrical nerve stimulation (TENS) procedures, maternal and/or fetal monitoring. Conventional biomedical electrodes are secured to the skin of a patient via a hydrogel and/or pressure sensitive adhesive. Hydrogels used in the construction of biomedical electrodes constitute a broad class of materials which swell extensively in water but are not completely water soluble. Such hydrogels are used in a variety of biomedical applications and may be applied in bulk forms which vary from clear to opaque and from a relatively stiff to a relatively soft consistency. Sometimes the bulk forms are reinforced by woven fabrics to increase the composite strength. Hydrogels have also been used as coatings for various biomedical applications.
In addition to using hydrogels for providing a secure connection between the electrode and the skin of a patient, an electrical cable or lead wire or metal stud is used to place the electrode in communication with an external electrical source. Various mechanisms for connecting a male/female terminal of the electrode to the complementary male/female terminal of the lead wire typically include “snap on” connectors, “pinch clip” arrangements, “twist on” couplings or magnetic couplings.
However, the arranging of a lead wire or metal stud on an electrode patch not only will increase the thickness of the resulting electrode patch, but also it will cause discomfort to any person attached thereby. Accordingly, a need exists for an electrode in which the lead wire or metal stud is removed. Additionally, a need exists for a wire-free and stud-free electrode capable of being attached to a garment, such electrode including a first side supporting a hydrogel having a first adhesive quality or property for selective or removable fixation to the skin of a patient, and second side supporting at least a pressure sensitive adhesive (PSA) having a second adhesive quality or property for selective or removable fixation to the garment.